Commit 3cfd4ab6 authored by Joel Becker's avatar Joel Becker Committed by Mark Fasheh
Browse files

ocfs2: Add the local node id to the handshake. 



This is the second part of the ocfs2_control handshake.  After
negotiating the ocfs2_control protocol, the daemon tells the filesystem
what the local node id is via the SETN message.

Signed-off-by: default avatarJoel Becker <joel.becker@oracle.com>
Signed-off-by: default avatarMark Fasheh <mfasheh@suse.com>
parent de870ef0

fs/ocfs2/stack_user.c

+173 −49
Original line number Diff line number Diff line
@@ -40,8 +40,18 @@ 
 * unknown, -EINVAL is returned.  Once the negotiation is complete, the

 * client can start sending messages.

 *

 * The T01 protocol only has one message, "DOWN".  It has the following

 * syntax:

 * The T01 protocol only has two messages.  First is the "SETN" message.

 * It has the following syntax:

 *

 *  SETN<space><8-char-hex-nodenum><newline>

 *

 * This is 14 characters.

 *

 * The "SETN" message must be the first message following the protocol.

 * It tells ocfs2_control the local node number.

 *

 * Once the local node number has been set, the "DOWN" message can be

 * sent for node down notification.  It has the following syntax:

 *

 *  DOWN<space><32-char-cap-hex-uuid><space><8-char-hex-nodenum><newline>

 *
@@ -58,11 +68,18 @@ 
 */

#define OCFS2_CONTROL_PROTO			"T01\n"

#define OCFS2_CONTROL_PROTO_LEN			4



/* Handshake states */

#define OCFS2_CONTROL_HANDSHAKE_INVALID		(0)

#define OCFS2_CONTROL_HANDSHAKE_READ		(1)

#define OCFS2_CONTROL_HANDSHAKE_VALID		(2)

#define OCFS2_CONTROL_MESSAGE_DOWN		"DOWN"

#define OCFS2_CONTROL_MESSAGE_DOWN_LEN		4

#define OCFS2_CONTROL_HANDSHAKE_PROTOCOL	(2)

#define OCFS2_CONTROL_HANDSHAKE_VALID		(3)



/* Messages */

#define OCFS2_CONTROL_MESSAGE_OP_LEN		4

#define OCFS2_CONTROL_MESSAGE_SETNODE_OP	"SETN"

#define OCFS2_CONTROL_MESSAGE_SETNODE_TOTAL_LEN	14

#define OCFS2_CONTROL_MESSAGE_DOWN_OP		"DOWN"

#define OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN	47

#define OCFS2_TEXT_UUID_LEN			32

#define OCFS2_CONTROL_MESSAGE_NODENUM_LEN	8
@@ -79,9 +96,35 @@ struct ocfs2_live_connection { 
struct ocfs2_control_private {

	struct list_head op_list;

	int op_state;

	int op_this_node;

};



/* SETN<space><8-char-hex-nodenum><newline> */

struct ocfs2_control_message_setn {

	char	tag[OCFS2_CONTROL_MESSAGE_OP_LEN];

	char	space;

	char	nodestr[OCFS2_CONTROL_MESSAGE_NODENUM_LEN];

	char	newline;

};



/* DOWN<space><32-char-cap-hex-uuid><space><8-char-hex-nodenum><newline> */

struct ocfs2_control_message_down {

	char	tag[OCFS2_CONTROL_MESSAGE_OP_LEN];

	char	space1;

	char	uuid[OCFS2_TEXT_UUID_LEN];

	char	space2;

	char	nodestr[OCFS2_CONTROL_MESSAGE_NODENUM_LEN];

	char	newline;

};



union ocfs2_control_message {

	char					tag[OCFS2_CONTROL_MESSAGE_OP_LEN];

	struct ocfs2_control_message_setn	u_setn;

	struct ocfs2_control_message_down	u_down;

};



static atomic_t ocfs2_control_opened;

static int ocfs2_control_this_node = -1;



static LIST_HEAD(ocfs2_live_connection_list);

static LIST_HEAD(ocfs2_control_private_list);
@@ -166,20 +209,21 @@ static void ocfs2_live_connection_drop(struct ocfs2_live_connection *c) 
	kfree(c);

}



static ssize_t ocfs2_control_cfu(void *target, size_t target_len,

static int ocfs2_control_cfu(void *target, size_t target_len,

			     const char __user *buf, size_t count)

{

	/* The T01 expects write(2) calls to have exactly one command */

	if (count != target_len)

	if ((count != target_len) ||

	    (count > sizeof(union ocfs2_control_message)))

		return -EINVAL;



	if (copy_from_user(target, buf, target_len))

		return -EFAULT;



	return count;

	return 0;

}



static ssize_t ocfs2_control_validate_handshake(struct file *file,

static ssize_t ocfs2_control_validate_protocol(struct file *file,

					       const char __user *buf,

					       size_t count)

{
@@ -188,16 +232,14 @@ static ssize_t ocfs2_control_validate_handshake(struct file *file, 


	ret = ocfs2_control_cfu(kbuf, OCFS2_CONTROL_PROTO_LEN,

				buf, count);

	if (ret != count)

	if (ret)

		return ret;



	if (strncmp(kbuf, OCFS2_CONTROL_PROTO, OCFS2_CONTROL_PROTO_LEN))

		return -EINVAL;



	atomic_inc(&ocfs2_control_opened);

	ocfs2_control_set_handshake_state(file,

					  OCFS2_CONTROL_HANDSHAKE_VALID);



					  OCFS2_CONTROL_HANDSHAKE_PROTOCOL);



	return count;

}
@@ -219,45 +261,92 @@ static void ocfs2_control_send_down(const char *uuid, 
	mutex_unlock(&ocfs2_control_lock);

}



/* DOWN<space><32-char-cap-hex-uuid><space><8-char-hex-nodenum><newline> */

struct ocfs2_control_message_down {

	char	tag[OCFS2_CONTROL_MESSAGE_DOWN_LEN];

	char	space1;

	char	uuid[OCFS2_TEXT_UUID_LEN];

	char	space2;

	char	nodestr[OCFS2_CONTROL_MESSAGE_NODENUM_LEN];

	char	newline;

};

/*

 * Called whenever configuration elements are sent to /dev/ocfs2_control.

 * If all configuration elements are present, try to set the global

 * values.  If not, return -EAGAIN.  If there is a problem, return a

 * different error.

 */

static int ocfs2_control_install_private(struct file *file)

{

	int rc = 0;

	int set_p = 1;

	struct ocfs2_control_private *p = file->private_data;



static ssize_t ocfs2_control_message(struct file *file,

				     const char __user *buf,

				     size_t count)

	BUG_ON(p->op_state != OCFS2_CONTROL_HANDSHAKE_PROTOCOL);



	if (p->op_this_node < 0)

		set_p = 0;



	mutex_lock(&ocfs2_control_lock);

	if (ocfs2_control_this_node < 0) {

		if (set_p)

			ocfs2_control_this_node = p->op_this_node;

	} else if (ocfs2_control_this_node != p->op_this_node)

		rc = -EINVAL;

	mutex_unlock(&ocfs2_control_lock);



	if (!rc && set_p) {

		/* We set the global values successfully */

		atomic_inc(&ocfs2_control_opened);

		ocfs2_control_set_handshake_state(file,

					OCFS2_CONTROL_HANDSHAKE_VALID);

	}



	return rc;

}



static int ocfs2_control_do_setnode_msg(struct file *file,

					struct ocfs2_control_message_setn *msg)

{

	ssize_t ret;

	char *p = NULL;

	long nodenum;

	struct ocfs2_control_message_down msg;

	char *ptr = NULL;

	struct ocfs2_control_private *p = file->private_data;



	/* Try to catch padding issues */

	WARN_ON(offsetof(struct ocfs2_control_message_down, uuid) !=

		(sizeof(msg.tag) + sizeof(msg.space1)));

	if (ocfs2_control_get_handshake_state(file) !=

	    OCFS2_CONTROL_HANDSHAKE_PROTOCOL)

		return -EINVAL;



	memset(&msg, 0, sizeof(struct ocfs2_control_message_down));

	ret = ocfs2_control_cfu(&msg, OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN,

				buf, count);

	if (ret != count)

		return ret;

	if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_SETNODE_OP,

		    OCFS2_CONTROL_MESSAGE_OP_LEN))

		return -EINVAL;



	if ((msg->space != ' ') || (msg->newline != '\n'))

		return -EINVAL;

	msg->space = msg->newline = '\0';



	nodenum = simple_strtol(msg->nodestr, &ptr, 16);

	if (!ptr || *ptr)

		return -EINVAL;



	if ((nodenum == LONG_MIN) || (nodenum == LONG_MAX) ||

	    (nodenum > INT_MAX) || (nodenum < 0))

		return -ERANGE;

	p->op_this_node = nodenum;



	return ocfs2_control_install_private(file);

}



static int ocfs2_control_do_down_msg(struct file *file,

				     struct ocfs2_control_message_down *msg)

{

	long nodenum;

	char *p = NULL;



	if (strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_DOWN,

		    strlen(OCFS2_CONTROL_MESSAGE_DOWN)))

	if (ocfs2_control_get_handshake_state(file) !=

	    OCFS2_CONTROL_HANDSHAKE_VALID)

		return -EINVAL;



	if ((msg.space1 != ' ') || (msg.space2 != ' ') ||

	    (msg.newline != '\n'))

	if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_DOWN_OP,

		    OCFS2_CONTROL_MESSAGE_OP_LEN))

		return -EINVAL;

	msg.space1 = msg.space2 = msg.newline = '\0';



	nodenum = simple_strtol(msg.nodestr, &p, 16);

	if ((msg->space1 != ' ') || (msg->space2 != ' ') ||

	    (msg->newline != '\n'))

		return -EINVAL;

	msg->space1 = msg->space2 = msg->newline = '\0';



	nodenum = simple_strtol(msg->nodestr, &p, 16);

	if (!p || *p)

		return -EINVAL;
@@ -265,9 +354,40 @@ static ssize_t ocfs2_control_message(struct file *file, 
	    (nodenum > INT_MAX) || (nodenum < 0))

		return -ERANGE;



	ocfs2_control_send_down(msg.uuid, nodenum);

	ocfs2_control_send_down(msg->uuid, nodenum);



	return count;

	return 0;

}



static ssize_t ocfs2_control_message(struct file *file,

				     const char __user *buf,

				     size_t count)

{

	ssize_t ret;

	union ocfs2_control_message msg;



	/* Try to catch padding issues */

	WARN_ON(offsetof(struct ocfs2_control_message_down, uuid) !=

		(sizeof(msg.u_down.tag) + sizeof(msg.u_down.space1)));



	memset(&msg, 0, sizeof(union ocfs2_control_message));

	ret = ocfs2_control_cfu(&msg, count, buf, count);

	if (ret)

		goto out;



	if ((count == OCFS2_CONTROL_MESSAGE_SETNODE_TOTAL_LEN) &&

	    !strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_SETNODE_OP,

		     OCFS2_CONTROL_MESSAGE_OP_LEN))

		ret = ocfs2_control_do_setnode_msg(file, &msg.u_setn);

	else if ((count == OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN) &&

		 !strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_DOWN_OP,

			  OCFS2_CONTROL_MESSAGE_OP_LEN))

		ret = ocfs2_control_do_down_msg(file, &msg.u_down);

	else

		ret = -EINVAL;



out:

	return ret ? ret : count;

}



static ssize_t ocfs2_control_write(struct file *file,
@@ -283,10 +403,11 @@ static ssize_t ocfs2_control_write(struct file *file, 
			break;



		case OCFS2_CONTROL_HANDSHAKE_READ:

			ret = ocfs2_control_validate_handshake(file, buf,

			ret = ocfs2_control_validate_protocol(file, buf,

							      count);

			break;



		case OCFS2_CONTROL_HANDSHAKE_PROTOCOL:

		case OCFS2_CONTROL_HANDSHAKE_VALID:

			ret = ocfs2_control_message(file, buf, count);

			break;
@@ -350,6 +471,8 @@ static int ocfs2_control_release(struct inode *inode, struct file *file) 
			       "an emergency restart!\n");

			emergency_restart();

		}

		/* Last valid close clears the node number */

		ocfs2_control_this_node = -1;

	}



out:
@@ -370,6 +493,7 @@ static int ocfs2_control_open(struct inode *inode, struct file *file) 
	p = kzalloc(sizeof(struct ocfs2_control_private), GFP_KERNEL);

	if (!p)

		return -ENOMEM;

	p->op_this_node = -1;



	mutex_lock(&ocfs2_control_lock);

	file->private_data = p;